As is known, the metal surfaces of many everyday objects are exposed to the attack of different substances (from simple atmospheric agents to those used in the various using methods), which in the long term change their initial appearance; for example, these coulth be the stainless steel surfaces used for stove tops exposed to the effect of heat, acids, abrasive substances, sharp blades, etc.
It is therefore necessary to protect these surfaces so as to maintain their initial features intact for as long as possible.
Products that have most recently come into use for the aforesaid purposes include “polymeric glasses”, which are compositions composed of aqueous solutions comprising silicates and/or polysilicates, silanes and sodium and/or lithium hydroxides applied to said metal surfaces in thin films which, once subjected to baking at suitable temperatures for the necessary times, form a protective vitreous layer (in this regard see, for example, WO 1995008515, U.S. Pat. Nos. 516,400, 4,162,169, 3,341,469, US 2006/0086281, U.S. Pat. Nos. 6,162,498, 8,173,221 B2).
The treatment guarantees resistance to oxidation, heat and corrosive substances and facilitates cleaning.
In order to perform their action effectively, said vitreous films must guarantee optimal adhesion and can be characterized by transparency.
It is also known that silver has an effective antibacterial action and that a surface treated with a coating based on silver salts or nanoparticles releases silver ions that interact with bacteria, destroying the cell membranes, although it is normally necessary to add large amounts of silver to the compositions to which this property is to be imparted, which heavily influences the final results, for example causing yellowing and tarnishing of materials.
Naturally, it would be important to be able to also add an antibacterial action to the simple protective action and to supply the product in different colors to make the industrial application thereof more attractive.